Base station, mobile station, reference signal transmission method, and channel quality measurement method

• US 10,425,852 B2
• Filed: 08/22/2014
• Issued: 09/24/2019
• Est. Priority Date: 09/26/2013
• Status: Active Grant

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Kakishima, Yuichi, Nagata, Satoshi, Kishiyama, Yoshihisa
• Primary Examiner(s): Zaidi, Iqbal
• Application Number:
  US15/024,366
• Publication Number:
  US 20160242060A1
• Time in Patent Office: 1,859 Days
• Field of Search: 370328-339, 445 82- 83, 375260-267, 455 82- 83
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/0626 Channel coefficients, e.g. channel state information [CSI]
• CPC Class Codes: H04B 7/0684 using different training sequences per antenna
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0057 Physical resource allocation for CQI
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 72/1263 Mapping of traffic onto schedule, e.g. scheduled allocation or multiplexing of flows

Abstract

A base station that communicates with a mobile station by using a plurality of antenna ports includes a mapping information communication unit configured to generate mapping of reference signals for measuring channel state information of the antenna ports by combining, within a resource block, mappings of reference signals for measuring the channel state information, the mappings being defined for a predetermined number or less of the antenna ports, and configured to communicate information indicating the generated mapping to the mobile station; a multiplexer configured to multiplex the reference signals for measuring the channel state information in one or more resource elements in the resource block in accordance with the generated mapping; and a transmitter configured to transmit the reference signals for measuring the channel state information.

Claims

1. A base station comprising:

a processor that communicates, to a mobile station, an index representing a first mapping of reference signals for measuring channel state information of a more than a predetermined number of antenna ports, the first mapping being configured by combining second mappings of the reference signals for measuring the channel state information, each of the second mappings being defined for the predetermined number or less antenna ports;

a multiplexer configured to multiplex the reference signals for measuring the channel state information in one or more resource elements in accordance with the first mapping; and

a transmitter configured to transmit the reference signals for measuring the channel state information,

wherein, in the one or more resource elements in which the reference signals for measuring the channel state information of the more than the predetermined number of antenna ports is multiplexed, a reference signal for measuring the channel state information of each antenna port number is mapped to a position determined in accordance with a predetermined rule.

2. A mobile station comprising:

a mapping information receiver configured to receive an index representing a first mapping of reference signals for measuring channel state information of more than a predetermined number of antenna ports, the first mapping being configured by combining second mappings of the reference signals for measuring the channel state information, each of the second mappings being defined for the predetermined number or less antenna ports;

a processor that measures the reference signals for measuring the channel state information based on the received index representing the first mapping, and that generates the channel state information; and

a transmitter configured to transmit the generated channel state information,

wherein, in one or more resource elements in which the reference signals for measuring the channel state information of the more than the predetermined number of antenna ports is multiplexed, a reference signal for measuring the channel state information of each antenna port number is mapped to a position determined in accordance with a predetermined rule.

3. A reference signal transmission method by a base station, the method comprising:

communicating, to a mobile station, an index representing a first mapping of reference signals for measuring channel state information of a more than a predetermined number of antenna ports, the first mapping being configured by combining second mappings of the reference signals for measuring the channel state information, each of the second mapping being defined for the predetermined number or less antenna ports;

multiplexing the reference signals for measuring the channel state information in one or more resource elements in accordance with the first mapping; and

transmitting the reference signals for measuring the channel state information,

wherein, in the one or more resource elements in which the reference signals for measuring the channel state information of the more than the predetermined number of antenna ports is multiplexed, a reference signal for measuring the channel state information of each antenna port number is mapped to a position determined in accordance with a predetermined rule.

4. A channel quality measurement method by a mobile station, the method comprising:

receiving an index representing a first mapping of reference signals for measuring channel state information of more than a predetermined number of antenna ports, the first mapping being configured by combining second mappings of the reference signals for measuring the channel state information, each of the second mappings being defined for the predetermined number or less antenna ports; and

measuring the reference signals for measuring the channel state information based on the received index representing the first mapping, and generating channel state information,

wherein, in one or more resource elements in which the reference signals for measuring the channel state information of the more than the predetermined number of antenna ports is multiplexed, a reference signal for measuring the channel state information of each antenna port number is mapped to a position determined in accordance with a predetermined rule.